The mango (Mangifera, indica L.) is king of the tropical fruits. This tasty relative of the cashew and pistachio is indigenous to India and southeast Asia, and is now found in tropical and subtropical lowlands throughout the world. Mangoes have been cultivated in India for more than 4,000 years, and they were brought to Florida in the early 1800s. The mango tree's oval fruit may be red, orange, purple, green, yellow or a combination, and its juicy flesh ranges from pale yellow to deep orange.
Young trees should be fertilized every month during their first year, according to the University of Florida Extension. Begin with a 1/4 lb. application and build up gradually to a 1 lb. application. After the first year, a quarterly application is sufficient. Use a 6-6-6 or 10-10-10 formula. The California Rare Fruit Growers says organic fertilizers are your best choice, because mango trees are subject to fertilizer burn.
When the tree begins bearing fruit, switch to a fertilizer with a 9- to 15-percent potash formulation and reduce the phosphoric acid to 2 to 4 percent.
If your garden soil pH is alkaline (registers above 7.0), give your tree a yearly nutritional spray of copper, zinc, manganese and boron for the first five years, recommends the UF Extension. After the fifth year, use a spray that contains only zinc and manganese. Apply boron in a spray or dry form each year at a very low rate (1/300th of the nitrogen rate). Drench your soil with iron in chelated form three times a year.
Neutral and Acidic Soils
If your mango tree is growing in a neutral (about 7.0) or acidic (below 7.0) soil, fertilize it annually with dry forms of iron, manganese, boron and zinc, either separately or in mixes. Spray with copper for added nutrients. Apply chelated iron as a soil drench or water-in non-chelated iron three times a year.